O munificent ones!
I've been working with binary strings, which, coming from an image file, can have any bin-value. The following behaviour caused a lot of head scratching till I found out where the problem was: 
my @strings=("ab30ff","30","ab1a30");
for (@strings){
    $_=pack ("H*",$_);
}
for my $b1 (@strings){
    print "here: ";
    while ($b1){
        my $b1=substr $b1,0,1,"";
        my $bits=unpack ("B*",$b1);
        print "$bits//";
    }
    print "\n";
}

here: 10101011//00110000//11111111//
here: 
here: 10101011//00011010//

[download]
As you can see, if \x30 comes at the end of the string or the string only consists of \x30, "while" breaks off. The strings come from a read-in filehandle, which was in binmode, but have been extracted and passed between subs. Is there any way to force "while" to treat it as binary here.
All suggestions gratefully received

In reply to while loop on binary : \x30 by sphalaris

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